The invention relates to controlling the movement of a structure. More particularly, the invention provides a method by which piezoelectric actuators, which are mounted or embedded on or in a structure adjacent to waveguides, such as optical fibers, provide controlled movement of such structures.
Optical fibers and piezoelectric actuators are well known. An opto-acoustic fuel quantity gauging system is disclosed by Ellinger in U.S. Pat. No. 4,677,305 (assigned to Simmonds Precision Products, Inc.). Griffiths in U.S. Pat. No. 4,654,520 issued Mar. 31, 1987 discloses a structural monitoring system using fiber optics. The use of microbend transducers which include mechanical amplifiers to facilitate detections of remote structural forces is disclosed by Asawa, et al. in U.S. Pat. No. 4,421,979. These transducers are located at discrete points on a structure. An optical fiber free of the structure is engaged periodically by the transducers so that reflections are only detectable from discrete locations. However, the structure is not moved by the transducers.
Kiraly in U.S. Pat. No. 4,400,642 discloses piezoelectric composite materials, in which a laminated structural device has the ability to change shape, position and resonant frequency without using discrete motive components. Kiraly cites Croswell, Jr. U.S. Pat. No. 3,930,626 as disclosing the use of structural wires employed to control the angular configuration of a fluid control system. Kiraly mentions that according to Croswell the structural elements that will expand or contract to produce curvature of the aerodynamic surface may include piezoelectric materials.
It is an object of the invention to provide a method of operating a piezoelectric member in response to movement of an optical fiber.
It is an object of the invention to provide a method of moving piezoelectric members in a structural member, such as an airfoil, in response to a signal produced from light emitted into optical fiber embedded in the airfoil.